This handler sets the `document` property of new annotations to metadata
extracted from `<meta>` and `<link>` tags on the page. It is unnecessary
however because the `Guest` class sets this property using either
`DocumentMeta.metadata` or `PDF.getMetadata`, depending on the document
type, before it emits the `beforeAnnotationCreated` event.

In PDFs this code is a serious hazard because if the
`beforeAnnotationCreated` event subscriber in `DocumentMeta` runs before
`AnnotationSync`'s corresponding event handler then DocumentMeta will
overwrite the PDF document-specific annotation metadata with generic
HTML document metadata - losing the critical `documentFingerprint`
property. Fortunately this problem did not occur because the `Guest`
constructor instantiates the `AnnotationSync` class before the
`DocumentMeta` class. Consequently AnnotationSync's
`beforeAnnotationCreated` event handler runs before DocumentMeta's and
pushes new annotations to the sidebar with the correct document metadata
before `DocumentMeta` overwrites it.

The ThreadList component has a required felid  `threads` but its value was undefined in tests. The value comes from the mocked version of `useRootThread.children`

The recent refactor to change the relationship between the `Guest` and `Sidebar`
classes broke PDF.js integration because the `PdfSidebar` class is no
longer able to modify the config that is passed to the `Guest` class.
Previously it would pass `PDF: {}` in the config to the `super()` call
which would then result in the `Guest` class loading the PDF
integration.

This now has to be done in the `index.js` module. We already had to do
this previously for ebooks. Now it has to be done for all scenarios.

If `make sure` or `make checkformatting` are the first command that are
run after version update that included prettier, the commands will use
the previous version of prettier.

With the recent changes in the gulp test command (#2989), everything
that could be achieved by `make servetest` can be done by options to the
`make test` target.

Removed @ts-ignore

Bumps [typescript](https://github.com/Microsoft/TypeScript) from 4.1.5 to 4.2.2.
- [Release notes](https://github.com/Microsoft/TypeScript/releases)
- [Commits](https://github.com/Microsoft/TypeScript/compare/v4.1.5...v4.2.2)
Signed-off-by: dependabot[bot] <support@github.com>

The `guest` argument is required but the `config` argument is now
optional. Swap them so that required arguments come before optional
ones and set a default value for `config`.

Change the relationship between the `Guest` and `Sidebar` classes from
one of inheritance to one where `Sidebar` receives a reference to the
`Guest` instance and calls methods on it or subscribes to events from
it. The `Guest` also no longer "owns" references to the bucket bar /
toolbar objects that logically belong to the sidebar. Instead it emits
events which the sidebar responds to.

This change makes the interface of the `Guest` used by the `Sidebar`
more explicit and ensures a better boundary between the two. This also
makes it easier for the `Sidebar` tests to be concerned only with the
interface of the `Guest` and not its implementation details. In future
this change will also make it possible to have a frame which does not
contain a sidebar but is not annotateable. We had a need for this
historically when integrating with epub viewers, although it was never
implemented.

Updating the tests for `PdfSidebar` was complicated by the fact that the
`PdfSidebar` tests are not pure unit tests. They instantiate the
`Sidebar` base class and so depend on many implementation details of it.
To make this change and others easier, the `PdfSidebar` tests have been
changed to mock the `Sidebar` base class. The steps involved in this are
non-obvious so I extracted the logic into a utility function.

 - Change `Sidebar` to no longer inherit `Guest` but accept it as a
   constructor argument
 - Remove direct references to the `BucketBar` and `ToolbarController`
   instances from the `Guest` class and instead emit events from the
   `Guest` which the `Sidebar` responds to.
 - Add a `mockBaseClass` testing helper in `src/test-util/mock-base.js`
   and change the `PdfSidebar` tests to use it, so that they are less
   coupled to `Sidebar` implementation details.

Bumps [@babel/core](https://github.com/babel/babel/tree/HEAD/packages/babel-core) from 7.12.17 to 7.13.8.
- [Release notes](https://github.com/babel/babel/releases)
- [Changelog](https://github.com/babel/babel/blob/main/CHANGELOG.md)
- [Commits](https://github.com/babel/babel/commits/v7.13.8/packages/babel-core)
Signed-off-by: dependabot[bot] <support@github.com>

Bumps [aws-sdk](https://github.com/aws/aws-sdk-js) from 2.848.0 to 2.853.0.
- [Release notes](https://github.com/aws/aws-sdk-js/releases)
- [Changelog](https://github.com/aws/aws-sdk-js/blob/master/CHANGELOG.md)
- [Commits](https://github.com/aws/aws-sdk-js/compare/v2.848.0...v2.853.0)
Signed-off-by: dependabot[bot] <support@github.com>

Bumps [@babel/preset-env](https://github.com/babel/babel/tree/HEAD/packages/babel-preset-env) from 7.12.17 to 7.13.8.
- [Release notes](https://github.com/babel/babel/releases)
- [Changelog](https://github.com/babel/babel/blob/main/CHANGELOG.md)
- [Commits](https://github.com/babel/babel/commits/v7.13.8/packages/babel-preset-env)
Signed-off-by: dependabot[bot] <support@github.com>

Bumps [eslint](https://github.com/eslint/eslint) from 7.20.0 to 7.21.0.
- [Release notes](https://github.com/eslint/eslint/releases)
- [Changelog](https://github.com/eslint/eslint/blob/master/CHANGELOG.md)
- [Commits](https://github.com/eslint/eslint/compare/v7.20.0...v7.21.0)
Signed-off-by: dependabot[bot] <support@github.com>

Bumps [core-js](https://github.com/zloirock/core-js/tree/HEAD/packages/core-js) from 3.9.0 to 3.9.1.
- [Release notes](https://github.com/zloirock/core-js/releases)
- [Changelog](https://github.com/zloirock/core-js/blob/master/CHANGELOG.md)
- [Commits](https://github.com/zloirock/core-js/commits/v3.9.1/packages/core-js)
Signed-off-by: dependabot[bot] <support@github.com>

Bumps [puppeteer](https://github.com/puppeteer/puppeteer) from 7.1.0 to 8.0.0.
- [Release notes](https://github.com/puppeteer/puppeteer/releases)
- [Changelog](https://github.com/puppeteer/puppeteer/blob/main/CHANGELOG.md)
- [Commits](https://github.com/puppeteer/puppeteer/compare/v7.1.0...v8.0.0)
Signed-off-by: dependabot[bot] <support@github.com>

Bumps [@octokit/rest](https://github.com/octokit/rest.js) from 18.2.0 to 18.3.0.
- [Release notes](https://github.com/octokit/rest.js/releases)
- [Commits](https://github.com/octokit/rest.js/compare/v18.2.0...v18.3.0)
Signed-off-by: dependabot[bot] <support@github.com>

The purpose of this PR is to be able to easily run karma tests in other
browsers without manually editing the karma configuration or making
local copies of the karma configuration.

Additions:

- `yarn test --no-browser` to avoid launching the default browser.
  It is up to the developer to run the tests in whatever browser she/he
  chooses by navigating to http://localhost:9876/.

- `yarn test --browser <browser>` run the tests in a different
  browser/s instead of the default browser. Chrome launcher comes by
  default with karma. Firefox, Safari and others can be installed
  independently.

Modifications:

- `yarn gulp test-watch` has been substituted by `yarn test --watch` for consistency.

The `disableShadowSidebar` flag and the corresponding behavior no longer
exists.

The `ToolbarController#getWidth` method started incorrectly returning 0
after 243c06d3. This commit moved the
content of the toolbar to a child of `ToolbarController._container` and
the `getWidth` method was not updated accordingly.

The incorrect result of `this.toolbar.getWidth()` in `Sidebar` later
resulted in an incorrect calculation of the sidebar's width and caused
`PdfSidebar` to think that the window was too narrow to support
side-by-side mode.

Fix the problem by updating `ToolbarController#getWidth` so that it
returns the correct value again.

Convert a statement into an if/else for readability.

- Remove `disableShadowSidebar` flag
- Simplify code structure
- Remove iframe from externalContainer on `destroy`.

Closes #2908

This prevents long lists from going off-screen and becoming unwieldy.

If the current user shows up in the filter list. (e.g they have annotations), then sort that user to the front of the list and add " (Me)" suffix to the end of the displayed name to make it easier for a user to find and filter their own annotations.

This small trick borrowed from
https://css-tricks.com/preventing-a-grid-blowout/ keeps the grid content
within the grid boundaries, thus improving the responsive design.

In a PR #3055, we remove reference to the plugin system for the
BucketBar and we create a property `bucketBar` in `Guest` class. I
overlook one of this reference in the `sidebar`.

This reverts commit 85f6023f.

This reverts commit e19983b0.

BucketBar is not used anymore as a plugin.

- Added types
- Moved out of the plugin directory
- Avoid extending from Delegator (unnecessary)

The sidebar component directs the opening of the notebook. This is for two reasons:

* it's a little bit easier to save the UI state of the current sidebar
  (immediately before the notebook is opened), in case in the future we
  want to restored it.

* to avoid adding additional events, like `show/hideSidebarControls`,
  that probably would be needed for granular control of the sidebar, in
  case the notebook would be directing the process of closing/re-opening
  the sidebar.

Because I am planning to introduce another method to hide the controls,
I renamed the hide/show methods in the sidebar and notebook components
to open/close. I also feel it describes better the visual outcome.

For consistency, I renamed the show/hideNotebook to open/closeNotebook.

Moved the user-filter below the heading and added a little bit of top
and bottom space.

Rename CSS class names for `Toolbar` component to match the component itself.
This component name is really overly generic but at least this brings
the CSS and Preact components into line.

One of the toolbar's classes was applied to a container element created
by `ToolbarController`. This class has been moved to an element created
by the `Toolbar` component for consistency. This means there is an
apparently redundant (no styling, one child) container div when looking
at the DOM structure for the toolbar + bucket bar. This will go away if
the whole sidebar container is made into a single Preact component in
future.

Rename all CSS classes used by the `AdderToolbar` component to follow
the `Component__element--modifier` syntax that we use for other
components. Also rename the `Adder.scss` file to match the Preact
component name.

This is not the correct solution, but as only one import is affected,
this is a simple workaround with no effect on other code.

Bumps [escape-string-regexp](https://github.com/sindresorhus/escape-string-regexp) from 1.0.5 to 4.0.0.
- [Release notes](https://github.com/sindresorhus/escape-string-regexp/releases)
- [Commits](https://github.com/sindresorhus/escape-string-regexp/compare/v1.0.5...v4.0.0)
Signed-off-by: dependabot[bot] <support@github.com>

Bumps [terser](https://github.com/terser/terser) from 5.5.1 to 5.6.0.
- [Release notes](https://github.com/terser/terser/releases)
- [Changelog](https://github.com/terser/terser/blob/master/CHANGELOG.md)
- [Commits](https://github.com/terser/terser/commits)
Signed-off-by: dependabot[bot] <support@github.com>

Bumps [core-js](https://github.com/zloirock/core-js) from 3.8.3 to 3.9.0.
- [Release notes](https://github.com/zloirock/core-js/releases)
- [Changelog](https://github.com/zloirock/core-js/blob/master/CHANGELOG.md)
- [Commits](https://github.com/zloirock/core-js/compare/v3.8.3...v3.9.0)
Signed-off-by: dependabot[bot] <support@github.com>

Because of recent changes in the sidebar (#2904), the BucketBar
component is no longer used as a plugin. @robertknight suggested to
remove all unneeded functionality.

Closes #2907